Video Bitstream Syntax Constraints for Single-Slice Subpicture Parsing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The changes in the high-level syntax structure of the bitstream due to the introduction of new tools in the Versatile Video Coding (VVC) standard have led to increased complexity and potential inconsistencies, which affect coding performance.

Innovation Solution

The proposed methods involve parsing and decoding video data by restricting the use of subpictures and color plane separation based on specific syntax elements, ensuring that a picture contains only one slice, and enforcing constraints on syntax elements to simplify the parsing of the slice header and reduce complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If existing video coding syntax is used, then compatibility with current standards is maintained, but the syntax becomes overly complex and difficult to implement

Engineering Contradiction:
Improveease of implementationVSAvoidsyntax complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent segments the video coding syntax into a hierarchical structure with high-level constructs that encapsulate complex operations. Instead of using flat, detailed syntax at every level, the invention introduces abstract syntax elements (such as prediction units, transformation units, and residue data) that can be instantiated in multiple ways, reducing the apparent complexity while maintaining implementation flexibility.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent creates universal syntax elements that can serve multiple functions. For example, the same syntax structure can handle different prediction modes, transformation types, and residue representations through parameter variations rather than requiring separate syntax for each case. This multi-functionality simplifies the overall syntax by reducing redundancy.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Manufacturing precision

If detailed syntax is provided for all coding operations, then implementation precision is improved, but the syntax length and processing overhead increase

Engineering Contradiction:
Improveimplementation precisionVSAvoidprocessing overhead
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent performs preliminary actions by pre-defining common operations and parameters in the syntax structure. Frequently used operations are standardized in advance, allowing implementations to reference these pre-defined elements rather than specifying every detail at runtime. This reduces processing overhead while maintaining precision through the pre-established syntax rules.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent achieves implementation precision through parameter changes rather than syntax expansion. By allowing a single syntax element to take on different parameter values (such as prediction mode indices, transformation types, or residue characteristics), the system maintains detailed implementation control without increasing syntax length or processing requirements.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If flexible coding options are provided, then adaptability to different video content is improved, but the complexity of selecting and managing options increases

Engineering Contradiction:
Improveadaptability to video contentVSAvoidsyntax structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent introduces dynamic syntax elements that can adapt their structure based on the video content being processed. The syntax allows for dynamic selection of prediction modes, transformation types, and residue handling methods depending on the specific coding situation. This dynamic capability provides adaptability while managing complexity through structured decision points rather than exhaustive option lists.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent uses intermediary syntax elements as mediators between the high-level coding decisions and the low-level implementation details. These intermediary elements (such as prediction unit parameters or transformation unit descriptors) serve as interfaces that translate flexible coding options into concrete operations, reducing the complexity of managing and selecting among multiple coding options.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP4122199B1High level syntax for video coding and decoding
Publication Date: 2026.05.13 CANON KK
  • EP4122199B1 patent drawingFigure 1
  • EP4122199B1 patent drawingFigure 2
  • EP4122199B1 patent drawingFigure 3

AI summary

There is described a method of decoding video data from a bitstream. The bitstream comprising video data corresponding to one or more slices. The decoding comprises parsing the syntax elements, and not permitting use of a subpicture and/or parsing of subpicture information in combination with at least one syntax element that indicates that a picture to be decoded contains only one slice. The bitstream is decoded using said syntax elements.